Randomized, double-blind, 3-month parallel study of the effects of pramipexole, pergolide, and placebo on Parkinsonian tremor.

We compared the antitremor effect of pramipexole, pergolide, or placebo in Parkinson's disease (PD). A double-blind, randomly controlled, parallel protocol was deployed to examine the effects of placebo, pergolide, and pramipexole [doses escalated to 1.5 mg three times daily (t.i.d.) over 3 months] on a compound Tremor Index (TI) and Unified Parkinson's Disease Rating Scale (UPDRS) part III. Thirty PD patients (19 men, 11 women; mean age 69 years, range 54-80 years; mean disease duration 3.9 years, range, 0.5-10 years) participated in the study, with 10 patients in each arm. Six subjects failed to complete the study (4 on pergolide and 2 on placebo). Analysis of covariance demonstrated strong evidence for a treatment effect on both TI and UPDRS III. There was no significant difference between the active treatments on either TI or UPDRS III. Both pergolide and pramipexole were significantly better than placebo. The results indicate that pergolide and pramipexole (1.5 mg t.i.d.) have similar anti-PD tremor and UPDRS III actions that are significantly superior to placebo. Patients on pergolide were more likely to drop out because of adverse events than those on pramipexole.